US20190000672A1

Movatterモバイル変換

Info

Publication number: US20190000672A1
Application number: US16/008,708
Authority: US
Inventors: Brian William McDonell
Original assignee: Novartis AG
Current assignee: Alcon Inc
Priority date: 2017-06-28
Filing date: 2018-06-14
Publication date: 2019-01-03

Abstract

The present disclosure discloses systems and methods for actuating a cutter of a vitrectomy probe. The systems and methods involve applying fluidic pressure to a fluidic amplifier or a fluidic oscillator of the vitrectomy probe to cause oscillatory movement of a component of the cutter to perform a cutting action.

Description

TECHNICAL FIELD

The present disclosure relates to ophthalmic surgery and surgical equipment and, more specifically, to systems and methods for actuating an inner cutter of a vitrectomy probe.

BACKGROUND

Ophthalmic surgery saves and improves the vision of tens of thousands of patients every year. However, given the sensitivity of vision to even small changes in the eye and the minute and delicate nature of many eye structures, ophthalmic surgery is difficult to perform and the reduction of even minor or uncommon surgical errors or modest improvements in accuracy of surgical techniques can make an enormous difference in the patient's vision after the surgery.

Ophthalmic surgery is surgery performed on the eye or any part of the eye. Ophthalmic surgery is regularly performed, for example, to repair retinal defects, repair eye muscles, remove cataracts or cancer, or to restore or improve vision. Vitreous humor or vitreous is contained in the posterior segment of the eye and is a clear gel-like substance that holds the retina in place. In some surgical procedures, a surgeon may need to remove some or all of the vitreous to allow access to the retina or other internal structures. In such procedures, the vitreous may be cut and aspirated out of the eye in a procedure called a vitrectomy.

SUMMARY

According to one aspect, the present disclosure describes a vitrectomy probe including a body defining a first diaphragm chamber; a cutter including tubular outer cutter coupled at a proximal end of the body; and a tubular inner cutter disposed within the tubular outer cutter and movable therewithin; and an actuating mechanism. The actuating mechanism includes a flexible diaphragm coupled to the body, the first diaphragm chamber disposed adjacent to a first side of the flexible diaphragm; and a fluidic amplifier. The fluidic amplifier includes an interaction region; a supply port in fluid communication with the interaction region; a first control port in fluid communication with the interaction region; a vent port through which fluid is vented from the fluidic amplifier; a splitter disposed at a distal end the interaction region and dividing the distal end of the interaction region into a first outlet and a second outlet; and a first vent line fluidically coupled to the first outlet of the interaction region and fluidically coupled to the vent port. The supply port may be operable to introduce a power stream of fluid into the interaction region. The first control port may be operable to introduce a first control jet of fluid into the interaction region. The first outlet may be fluidically coupled to the first diaphragm chamber and the second outlet fluidically coupled to the vent port.

Another aspect of the disclosure encompasses a method for actuating a cutter of a vitrectomy probe including supplying a power stream to a fluidic amplifier disposed within the vitrectomy probe. A tubular inner cutter of the cutter may be disposed in a first position when the power stream is supplied to the fluidic amplifier. A control jet may be selectively supplied to the fluidic amplifier with such that when the control jet is supplied. The power stream may be redirected from a first path to a second within the fluidic amplifier to actuate the tubular inner cutter from the first position to a second position. When the control jet is not supplied, the power stream may be returned to the first path within the fluidic amplifier, causing the tubular inner cutter to return to the first position.

Another aspect of the disclosure encompasses a method for actuating a tubular inner cutter of a vitrectomy probe including supplying a power stream to a fluidic amplifier disposed within the vitrectomy probe, a tubular inner cutter of the cutter disposed in a first position when the power stream is supplied to the fluidic amplifier and selectively supplying a control jet to the fluidic amplifier such that: when the control jet is supplied, the power stream is redirected from a first path to a second within the fluidic amplifier to actuate the tubular inner cutter from the first position to a second position, and when the control jet is not supplied, the power stream is returned to the first path within the fluidic amplifier, causing the tubular inner cutter to return to the first position.

A further aspect of the disclosure encompasses a vitrectomy probe including a body defining a first diaphragm chamber; a tubular outer cutter coupled at a proximal end to the body; an aspiration port formed in a distal end of the tubular outer cutter; a tubular inner cutter disposed within the tubular outer cutter, the tubular inner cutter movable within the tubular outer cutter; and an actuating mechanism operable to actuate the tubular inner cutter. The actuating mechanism may be housed in the body and include a flexible diaphragm coupled to the body and a fluidic oscillator. The first diaphragm chamber may be disposed adjacent to a first side of the flexible diaphragm. The fluidic oscillator may include an interaction region; a supply port in fluid communication with the interaction region, the supply port operable to introduce a power stream of fluid into the interaction region; a vent port through which fluid is vented from the fluidic oscillator; a first feedback channel offset from the interaction region by a first wall, the first feedback channel operable to redirect the power stream of fluid in a first direction; a second feedback channel offset from the interaction region by a second wall, the second feedback channel operable to redirect the power stream in a second direction opposite the first direction; a nozzle at the distal end of the interaction region; a first outlet extending from the nozzle and fluidically coupled to the first diaphragm chamber; a second outlet extending from the nozzle and fluidically coupled to the vent port; and a first vent line fluidically coupled to the first outlet of the fluidic oscillator and fluidically coupled to the vent port.

Another aspect of the disclosure includes a method for actuating a cutter of a vitrectomy probe including supplying a power stream to a fluidic oscillator disposed within the vitrectomy probe, a tubular inner cutter of the cutter disposed in a first position when the power stream is supplied to the fluidic oscillator; and configuring the fluidic oscillator such that the power stream interacts with a first feedback channel and a second feedback channel so that the power stream oscillates and is redirected to actuate the tubular inner cutter between the first position and a second position.

The various aspects may include one or more of the following features. A spring may abut the flexible diaphragm along a second side of the flexible diaphragm opposite the first side. The splitter may be offset from the supply port such that the splitter redirects a flow from the supply port into the first output port. The splitter may be offset from the supply port such that the splitter redirects a flow from the supply port into the second outlet. The splitter may be offset from the supply port such that the splitter redirects a flow from the supply port into the first outlet. The interaction region may include a sidewall shaped to promote attachment of the power stream to the sidewall. The splitter is aligned with the supply port such that the splitter redirects a flow from the supply port substantially equally into the first outlet and the second outlet. A second diaphragm chamber may be disposed adjacent to a second side of the flexible diaphragm. The second outlet may be fluidically coupled to the second diaphragm chamber. A second vent line may extend from the second outlet to the vent port. The splitter may be offset from the supply port such that the splitter redirects a flow from the supply port into the first outlet of the interaction region. The interaction region may include a sidewall shaped to promote attachment of the power stream to the sidewall. A second control port may be fluidically coupled to the interaction region, the second control portion operable to introduce a second control jet into the interaction region. The splitter may be aligned with the supply port such that the splitter divides a power stream flow from the supply port substantially equally into the first outlet of the interaction region and the second outlet of the interaction region.

The various aspects may include one or more of the following features. Actuation a cutter of a vitrectomy probe may also include determining a desired cutting rate of the cutter; configuring the vitrectomy probe and the fluidic amplifier such that the desired cutting rate for the vitrectomy probe is determined by and corresponds to a desired frequency of the control jet that is supplied to the fluidic amplifier; setting the control jet to a desired frequency, thereby setting the desired cutting rate for the vitrectomy probe; and supplying the control jet with a selected pressure so that the tubular inner cutter is actuated to either the first position or the second position. Actuation of a cutter of a vitrectomy probe may also include determining a desired cutting rate of the cutter; configuring the fluidic oscillator such that the desired cutting rate for the cutter corresponds to a desired frequency of the power stream oscillation; setting the desired cutting rate of the cutter by setting the power stream to a desired pressure level to produce the desired frequency of the power stream oscillation; and supplying the power stream at a selected pressure so that the tubular inner cutter oscillates at the desired frequency.

The various aspects may also include one or more of the following features. A second diaphragm chamber may be disposed on a second side of the flexible diaphragm opposite the first side. A second vent line may extend from the second outlet to the vent port. The first outlet of the fluidic oscillator may be fluidically coupled to one of the first diaphragm chamber or the second diaphragm chamber. The second outlet of the fluidic oscillator may be fluidically coupled to the other of the first diaphragm chamber or the second diaphragm chamber. A spring may abut the flexible diaphragm along a second side of the flexible diaphragm opposite the first side. The fluidic oscillator may also include a splitter that separates the first outlet from the second outlet.

The above systems and/or apparatuses may be used with the above methods and vice versa. In addition, any system or apparatus described herein may be used with any method described herein and vice versa. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, which are not to scale and in which like numerals refer to like features.

FIG. 1 shows an example system for performing a vitrectomy including a schematic representation of a system for actuating an inner cutter of a vitrectomy probe.

FIG. 2 is a schematic representation of an example vitrectomy probe incorporating a fluidic amplifier within a double acting actuating mechanism;

FIG. 3 is a schematic representation of another example vitrectomy probe incorporating a fluidic amplifier within a double-acting actuating mechanism.

FIG. 4 is a schematic representation of still another vitrectomy probe incorporating a fluidic oscillator within a double-acting actuating mechanism.

FIG. 5 is a schematic representation of an example vitrectomy probe incorporating a fluidic amplifier within a single-acting actuating mechanism.

FIG. 6 is a schematic representation of a vitrectomy probe incorporating a fluidic oscillator within a single-acting actuating mechanism.

FIGS. 7-11 are schematic representations of various example fluidic amplifiers.

FIG. 12 is a schematic representation of an example fluidic oscillator.

FIGS. 13-15 are schematic representations of various example fluidic amplifiers.

FIG. 16 is a schematic representation of another example fluidic oscillator.

FIG. 17 is a flowchart of an example method for actuating an inner cutter of a vitrectomy probe.

FIG. 18 is a flowchart of another example method for actuating an inner cutter of a vitrectomy probe.

DETAILED DESCRIPTION

In the following description, details are set forth by way of example to facilitate an understanding of the disclosed subject matter. It should be apparent to a person of ordinary skill in the field, however, that the disclosed embodiments are exemplary and not exhaustive of all possible embodiments. Thus, it should be understood that reference to the described example is not intended to limit the scope of the disclosure. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one implementation may be combined with the features, components, and/or steps described with respect to other implementations of the present disclosure.

The present disclosure provides systems and methods for actuating an inner cutting portion of a vitrectomy probe. The systems and methods use a fluidic amplifier or a fluidic oscillator within a vitrectomy probe to produce a pressure profile that is exerted on a flexible diaphragm within an actuating mechanism. A fluidic oscillator is a fluidic device that resonates in response to a constant fluidic input. A fluidic amplifier theoretically produces fluidic output in response to a constant fluidic input. A power stream is supplied to the amplifier by a pressure source. One or more control jets is supplied to the amplifier to drive the amplifier between various configurations. When the amplifier is in these various configurations the pressure profiles cause the diaphragm to actuate an inner cutter of a vitrectomy probe. A power stream is supplied to the oscillator by a pressure source. The power stream begins to oscillate as feedback currents are generated by the power stream's interaction with the internal structures of the fluidic oscillator, which are described below in detail. These oscillations cause pressure profiles that cause the diaphragm to actuate the inner cutter of a vitrectomy probe.

In a vitrectomy, the surgeon inserts small surgical instruments into the eye, such as a vitrectomy probe. Vitrectomy probes typically include a cutter that includes a hollow outer cutter and a hollow inner cutter. The inner cutter is arranged coaxially with and movably disposed within the hollow outer cutter. The cutter also includes an aspiration port formed in the outer cutter near the distal end thereof. Vitreous is aspirated into the open aspiration port, and the inner cutter is actuated and moved past the aspiration port, effectively closing the aspiration port. When the aspiration port closes, a cutting surface formed on a distal end of the inner cutter (generally a distal edge of the inner cutter) cooperates with a cutting edge of the aspiration port to cut the vitreous. In some instances, a distal edge and a proximal edge of the aspiration port may form cutting edges for severing vitreous. The severed vitreous is then aspirated away through the inner cutter. Some vitrectomy probes may also include a second aspiration port formed in the inner cutter near the distal end thereof. This second aspiration port includes a cutting edge and allows for vitreous to be aspirated, cut, and aspirated away twice during a single cycle of actuation for the vitrectomy probe.

The inner cutter may be actuated using various methods and actuating mechanisms. For example, the inner cutter may be moved from a proximal position to a distal position by applying sufficient pressure against a piston or diaphragm assembly to overcome a mechanical spring. When the pressure is reduced below a given threshold, the spring returns the inner cutter from the distal position to the proximal position. Alternatively, the inner cutter may be moved by creating a pressure differential across a piston or diaphragm assembly. The inner cutter may be placed in the distal position using a first source of pressure. The inner cutter may then be moved to the proximal position using a second source of pressure. Although pressure may exist on both sides of the piston or diaphragm assembly, creating a sufficient pressure differential will actuate the inner cutter.

In many conventional vitrectomy probes, the pressure used to actuate the inner cutter is controlled at a remote console. Long drive line tubes add resistance, i.e., head loss, and volume to the pressure control system. This arrangement reduces the ability to produce rapid changes in the actuator pressures, thereby limiting the cutting rate that can be achieved by the vitrectomy probe. Operating at higher cutting rates reduces the aspiration time between cuts, the turbulence of vitreous, and traction during cutting, which in turn helps prevent retinal injury or surgical complications that result from vitreous cutting.

Referring now to the figures,FIG. 1 is asystem100 for actuating an inner cutter of a vitrectomy probe. As shown, thesystem100 provides avitrectomy probe200 inserted into aneye102. Theeye102 is not part of thesystem100, but is shown to better illustrate how the system may be used. Thesystem100 also may include other

surgical instruments

104 and106, which may be, for example, an illuminator, an aspirator, or an infusion cannula. Thesystem100 also includes aprocessor110 and apressure control device112. In some implementations, theprocessor110 and thepressure control device112 may be located in or otherwise form a part of a surgical console. Thesurgical microscope108 is not part of thesystem100, but thesurgical microscope108 is shown to better illustrate how thesystem100 may be used.

As shown, during a vitrectomy, thevitrectomy probe200 and the other

surgical instruments

104 and106 are inserted into theeye102. Thesurgical microscope108 is used to observe the vitrectomy and the

surgical instruments

104 and106 in theeye102. Theprocessor110 is configured to communicate with thepressure control device112 to control the intraocular pressure within the eye, such as by, for example, controlling the infusion pressure of fluid (e.g., a balanced salt solution) delivered to the eye and an aspiration pressure associated with withdrawing materials from the eye. Consequently, thepressure control device112 is operable to control the aspiration pressure applied to thevitrectomy probe200. In some implementations, theprocessor110 and thepressure control device112 are configured to control, for example, a power stream, a control jet or jets, a pressure level for both the power stream and the control jet(s), and the desired cutting rate of the vitrectomy probe. The power stream, the one or more control jets, and associated pressures thereof are described in more detail below.

Thepressure control device112 is fluidically coupled to thevitrectomy probe200, as shown in more detail inFIG. 2 throughFIG. 6. Fluid that passes through the vitrectomy probes as described herein may be any fluid suitable to actuate the inner cutter. For instance, the fluid may be air or a liquid, particularly a liquid safe for use in a surgical setting, such as water or saline. For example, a balanced salt solution, such as BSS® or BSS PLUS® produced by Alcon Laboratories, Inc., located at 6201 South Freeway, Fort Worth, Tex. 76134, may be used. Thepressure control device112 may be configured with a spool or poppet pneumatic valve or with a high speed pneumatic valve (referred to collectively hereinafter as “high speed valve”). U.S. patent application Ser. No. 15/091686 (Publication No. 2016-0296370 A1), the entire contents of which are incorporated herein by reference, describes examples of a high speed pneumatic valve. The high speed pneumatic valves described in application Ser. No. 15/091686 allow for rapid transition between fluid supply and fluid exhaust. The high speed pneumatic valves continuously rotate in a single axial direction and rapidly positions ports of an instrument to be in fluid communication with either a fluid supply or a fluid exhaust.

The power stream pressure level may be based on the characteristics of the diaphragm that is used in the actuating mechanism of the vitrectomy probe. The power stream pressure level may also be set in relation to the level of the control jet pressure, and vice versa. The control jet pressure level may be based on the characteristics of the diaphragm that is used in the actuating mechanism of the vitrectomy probe. The control jet pressure level may also be set in relation to the level of the power stream pressure. The control jet pressure level may be smaller in magnitude than the power stream pressure level. Depending on the stage of the vitrectomy surgery, the user may desire a specific cutting rate of the vitrectomy probe. The cutting rate may correlate with the frequency of changes in the control jet pressure. The desired cutting rate of the vitrectomy probe may be defined by the user and one or multiple cutting rates may be used throughout the vitrectomy surgery. The user may select a desired cutting rate and duty cycle. Each power stream pressure level and each control jet pressure level may be determined by theprocessor110, and one or multiple power stream pressures and control jet pressures may be used throughout the vitrectomy surgery.

Theprocessor110 may include, for example a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret and/or execute program instructions and/or process data. In some embodiments, theprocessor110 may interpret and/or execute program instructions and/or process data stored in a memory. The memory may be configured in part or whole as application memory, system memory, or both. The memory may include any system, device, or apparatus configured to hold and/or house one or more memory modules. Each memory module may include any system, device, or apparatus configured to retain program instructions and/or data for a period of time (e.g., computer-readable media). The various servers, electronic devices, or other machines described may contain one or more similar such processors or memories for storing and executing program instructions for carrying out the functionality of the associated machine.

FIG. 2 is a schematic representation of anexample vitrectomy probe200a.As shown,vitrectomy probe200ahas abody202 and acutter203. Thecutter203 includes anouter cutter206, aninner cutter208 and anaspiration port210 formed in theouter cutter206. Theouter cutter206 is attached at aproximal end204 to adistal end211 of thebody202 and includes a closeddistal end205. Theinner cutter208 is positioned concentrically within theouter cutter206 as well as within and through thebody202. Theinner cutter208 is hollow to form apassage207 and open at both thedistal end209 andproximal end219. Thedistal end209 of theinner cutter208 includes a cutting surface to allow for tissue to be cut during actuation of thecutter203. Theaspiration port210 is positioned toward thedistal end205 of theouter cutter206 and extends radially through theouter cutter206. Thedistal end215 andproximal end213 of theaspiration port210 may have cutting surfaces to allow for tissue to be cut during actuation. The one or more cutting surfaces of theaspiration port210 cooperate with the cutting surface of theinner cutter208 to sever material that is drawn into thecutter203 via theaspiration port210. The severed material is then aspirated away through thepassage207 in theinner cutter208.

Within thebody202, thevitrectomy probe200aalso has adiaphragm chamber212 that is divided into aproximal diaphragm chamber212aand adistal diaphragm chamber212b.Theproximal diaphragm chamber212aand thedistal diaphragm chamber212bare separated by aflexible diaphragm214. Theflexible diaphragm214 may be coupled to thebody202 along an outer periphery thereof. Thevitrectomy probe200aalso includes afluidic amplifier400, apower stream port216, a firstcontrol jet port218, avent port220, and a secondcontrol jet port222. As shown inFIG. 2, thefluidic amplifier400 is a general representation of various example fluidic amplifiers that are further described in reference toFIG. 7 throughFIG. 9.

In some implementations, theinner cutter208 is rigidly coupled to theflexible diaphragm214 such that, when theflexible diaphragm214 experiences a pressure differential betweendistal diaphragm chamber212bandproximal diaphragm chamber212athat is sufficient to displace the flexible diaphragm214 (e.g., a pressure differential that overcomes the frictional resistance and inertia of the moving parts of thevitrectomy probe200a), theflexible diaphragm214 is displaced, thus actuating theinner cutter208. When oscillatory pressure differentials are created between thedistal diaphragm chamber212band theproximal diaphragm chamber212a,theinner cutter208 is actuated in a reciprocal manner at a desired cutting rate. The cutting rate of theinner cutter208 and, hence, thecutter203, varies in response to the rate of oscillation of the pressure differentials within theproximal diaphragm chamber212aand thedistal diaphragm chamber212b.

When the pressure in theproximal diaphragm chamber212ais greater than the pressure in thedistal diaphragm chamber212b,theinner cutter208 is actuated in the direction of thearrow240. As theinner cutter208 is actuated, thedistal end209 of theinner cutter208 also moves in the direction of thearrow240 from a position proximal to theaspiration port210 to a position distal of theaspiration port210. When the pressure in thedistal diaphragm chamber212bis sufficiently greater than the pressure inproximal diaphragm chamber212aso as to cause theinner cutter208 to move (e.g., a pressure differential between thedistal diaphragm chamber212bandproximal diaphragm chamber212asuch that the pressure overcomes the frictional resistance and inertia of the moving parts of thevitrectomy probe200a), theinner cutter208 is actuated in the direction of thearrow230. As a result, theinner cutter208 is returned to its initial position, passing from the position distal to theaspiration port210 to the position proximal to theaspiration port210. In some instances, thevitrectomy probe200amay include a mechanism to adjust the proximal position of theinner cutter208 relative to theaspiration port210, and this proximal position may be varied by a user, such as a surgeon, before, during, or after a surgical procedure.

When theinner cutter208 is in the proximal position, vacuum pressure applied to thepassage207 draws tissue (e.g., vitreous) or other materials into theaspiration port210. The vacuum pressure may be applied continuously or intermittently. When theinner cutter208 is in the distal position, the cutting surfaces on theinner cutter208 and theaspiration port210 formed in theouter cutter206 cut the tissue that has been drawn into theaspiration port210. The vacuum pressure then aspirates the cut tissue and other materials through thepassage207 formed in theinner cutter208 in the direction of thearrow230. The aspirated materials may be collected in acollection chamber217. Theinner cutter208 is then actuated in the direction of thearrow230, returning theinner cutter208 to the proximal position to allow for further aspiration.

In some implementations, theinner cutter208 may also have a port formed therein proximal to thedistal end209. A distal end of the port formed in theinner cutter208 may have one or more cutting surfaces to allow for tissue to be cut during actuation. Thus, in some implementations, the port formed in theinner cutter208, in combination with theaspiration port210, allows thevitrectomy probe200ato perform two cuts during each actuation cycle of theinner cutter208.

Thepower stream port216, the firstcontrol jet port218, thevent port220, and the secondcontrol jet port222 are each fluidically coupled to thepressure control device112. As shown inFIG. 2, thepower stream port216, the firstcontrol jet port218, thevent port220, and the secondcontrol jet port222 are also fluidically coupled to thefluidic amplifier400. Thepressure control device112 supplies fluid to thevitrectomy probe200ato actuate theinner cutter208. Theprocessor110, shown inFIG. 1, and thepressure control device112 regulate parameters, for example, pressure level and cycle frequency, of the power stream and the control jets.

FIG. 3 is a schematic representation of anexample vitrectomy probe200b.Thevitrectomy probe200bis similar to thevitrectomy probe200aas described above in reference toFIG. 2. In particular, thebody202, thecutter203, theouter cutter206, thepassage207, theinner cutter208, theaspiration port210, thediaphragm chamber212, and theflexible diaphragm214 all function and interact in the same way as described above in reference toFIG. 2.

Thevitrectomy probe200balso includes afluidic amplifier500, apower stream port216, acontrol jet port218, and avent port220. As shown inFIG. 3, thefluidic amplifier500 is a general representation of various example fluidic amplifiers that are further described in reference toFIGS. 10 and 11.FIG. 3 illustrates avitrectomy probe200bwith a singlecontrol jet port218. Thefluidic amplifier500 included within thevitrectomy probe200bis configured to operate with the singlecontrol jet port218 as opposed to the two control jet ports included within thevitrectomy probe200a.Otherwise thecontrol jet port218, thepower stream port216, and thevent port220 operate in the same way as already described above in reference toFIG. 2. InFIG. 3, thecontrol jet port218, thepower stream port216, and thevent port220 are all fluidically coupled to thefluidic amplifier500.

FIG. 4 is a schematic representation of anotherexample vitrectomy probe200c.Thevitrectomy probe200cis similar to the vitrectomy probes200aand200bshown inFIGS. 2 and 3, respectively. In particular, thebody202, thecutter203, theouter cutter206, thepassage207, theinner cutter208, theaspiration port210, thediaphragm chamber212, and theflexible diaphragm214 all function and interact in the same way as described above in reference toFIGS. 2 and 3.

Thevitrectomy probe200calso includes afluidic oscillator600, apower stream port216, and avent port220. As shown inFIG. 4, thefluidic oscillator600 is a general representation of an example fluidic oscillator that is further described in reference toFIG. 12.FIG. 4 illustrates avitrectomy probe200cthat does not require a control jet port to function. Thefluidic oscillator600 included within thevitrectomy probe200cis configured to operate without the need for a control jet port. Otherwise thepower stream port216 and thevent port220 operate in the same way as already described above in reference toFIG. 2. InFIG. 4, thepower stream port216 and thevent port220 are fluidically coupled to thefluidic oscillator600.

FIG. 5 is a schematic representation of a furtherexample vitrectomy probe200d.Thevitrectomy probe200dis similar to the vitrectomy probes200a,200b,and200cshown inFIGS. 2, 3, and 4, respectively. In particular, thebody202, thecutter203, theouter cutter206, thepassage207, theinner cutter208, and theaspiration port210 all function and interact in the same way as described above in reference toFIGS. 2, 3, and 4.

Within thebody202, thevitrectomy probe200dalso includes adiaphragm chamber312 and aflexible diaphragm214. Thediaphragm chamber312 is disposed proximal and adjacent to theflexible diaphragm214. Thevitrectomy probe200dalso includes afluidic amplifier700, apower stream port216, acontrol jet port218, and avent port220. Thevitrectomy probe200dalso includes a spring, such as acoil spring322. Theinner cutter208 extends through the center of thecoil spring322. In some implementations, aproximal end321 of thecoil spring322 may be rigidly coupled to theflexible diaphragm214 and adistal end323 of thecoil spring322 may be rigidly coupled to thebody202. In other implementations, thecoil spring322 may be unattached to theflexible diaphragm214, thebody202, or both. For example, in some instances, an end of thecoil spring322 may abut, either directly or indirectly, theflexible diaphragm214.

Thecoil spring322 provides a biasing force that biases theflexible diaphragm214 and theinner cutter208 in the direction of thearrow230, such as when theflexible diaphragm214 is displaced in the direction of thearrow240. Thecoil spring322 operates to return theflexible diaphragm214 and theinner cutter208 back to an initial position in the direction of thearrow230 once pressure within thediaphragm chamber312 has been reduced to a selected level or removed altogether. Although thecoil spring322 is provided as an example biasing element operable to provide a biasing force to theflexible diaphragm214, the scope of the disclosure is not so limited. Rather, any type of spring, such as a Belleville washer, a torsion spring, an extension spring, or any other type of spring may be used.

Theinner cutter208 may be rigidly coupled toflexible diaphragm214 such that, whenflexible diaphragm214 is displaced by a pressure withindiaphragm chamber312 that is sufficient to overcome the biasing force ofcoil spring322, theinner cutter208 is actuated. When an oscillatory pressure is supplied to thediaphragm chamber312, theinner cutter208 actuates in a reciprocal manner at a desired cutting rate. As theinner cutter208 is actuated, thedistal end209 ofinner cutter208 moves distally in the direction ofarrow240 from a position proximal to theproximal end213 ofaspiration port210 to a position distal of thedistal end215 of theaspiration port210. Thevitrectomy probe200dmay be configured so that, when the pressure withindiaphragm chamber312 is not sufficient to overcome the biasing force of thecoil spring322, theinner cutter208 is actuated in the direction ofarrow230 and when the pressure within thediaphragm chamber312 is sufficient to overcome the biasing force of thecoil spring322, theinner cutter208 is actuated in the direction ofarrow240.

Apower stream port216, acontrol jet port218, and avent port220 are each fluidically coupled to apressure control device112. Thepower stream port216 and thecontrol jet port218 are also fluidically coupled to thefluidic amplifier700. Thepressure control device112 supplies fluid to thevitrectomy probe200dfor actuation of theinner cutter208. Theprocessor110 and thepressure control device112 regulate parameters, for example, pressure level and cycle frequency, of the power stream and control jet.

FIG. 6 is a schematic representation of another example vitrectomy probe200e.The vitrectomy probe200eis similar to thevitrectomy probe200dshown inFIG. 5. In particular, thebody202, thecutter203, theouter cutter206, thepassage207, theinner cutter208, theaspiration port210, thediaphragm chamber312, and theflexible diaphragm214 all function and interact in the same way as described above in reference toFIG. 5.

The vitrectomy probe200ealso includes afluidic oscillator800, apower stream port216, and avent port220. As shown inFIG. 6, thefluidic oscillator800 is a general representation of an example fluidic oscillator that is further described in reference toFIG. 16.FIG. 6 illustrates a vitrectomy probe200ethat does not require a control jet port to function. Thefluidic oscillator800 included within the vitrectomy probe200eis configured to operate without the need for a control jet port. Otherwise thepower stream port216 and thevent port220 operate in the same way as already described above in reference toFIG. 5. InFIG. 6, thepower stream port216 and thevent port220 are fluidically coupled to thefluidic oscillator800.

FIG. 7 is a schematic representation of a fluidic amplifier of a type included in thevitrectomy probe200a.Thefluidic amplifier400afunctions to actuate theinner cutter208 of thevitrectomy probe200a.Thefluidic amplifier400ahas apower stream inlet402, a firstcontrol jet inlet404, a secondcontrol jet inlet406 and aninteraction region408a.Thepower stream inlet402 is fluidically coupled to thepower stream port216. The firstcontrol jet inlet404 is fluidically coupled to thecontrol jet port218. The secondcontrol jet inlet406 is fluidically coupled to thecontrol jet port222. Thepower stream inlet402, the firstcontrol jet inlet404, and the secondcontrol jet inlet406 feed into or connect to theproximal end407 ofinteraction region408a.Thefluidic amplifier400aalso includes asplitter410, adistal pressure outlet412, and aproximal pressure outlet414. Thesplitter410 is located at thedistal end409 of theinteraction region408aand redirects flow from thepower stream inlet402, the firstcontrol jet inlet404, and the secondcontrol jet inlet406. Thesplitter410 is aligned with thepower stream inlet402 so that direct flow from thepower stream inlet402 is substantially equally split between thedistal pressure outlet412 and theproximal pressure outlet414. As shown, thedistal pressure outlet412 is fluidically coupled to thedistal diaphragm chamber212b,and theproximal pressure outlet414 is fluidically coupled to theproximal diaphragm chamber212a.The term “substantially” in the context of “substantially equal” means that the described items, e.g., fluid flows, are essentially the same but may experience slight variations. In the context of fluid flows, the slight variations may be the result of continuous fluctuations during operation of fluidic amplifiers or fluidic oscillators described herein, slight variations in the configurations described herein (e.g., a slight variances in the position of the splitter relative to the outlets), or other aspects that may cause slight variances so as to cause the flows to vary slightly from being equal.

Thefluidic amplifier400aalso has adistal vent line416, aproximal vent line418, and amain vent line420. Thedistal vent line416 is fluidically coupled to thedistal pressure outlet412. Thedistal vent line416 is positioned so that, when pressure increases in thedistal diaphragm chamber212b,excess pressure can be vented through thedistal vent line416 so as to prevent backflow through theinteraction region408a.Theproximal vent line418 is fluidically coupled to theproximal pressure outlet414. Theproximal vent line418 is positioned so that, when pressure increases in theproximal diaphragm chamber212a,excess pressure can be vented through theproximal vent line418 so as to prevent backflow through theinteraction region408a.Both thedistal vent line416 and theproximal vent line418 are fluidically coupled to themain vent line420. Themain vent line420 is fluidically coupled to thevent port220. The fluid that is vented throughvent port220 may then be exhausted at a location remote from thevitrectomy probe200, for example, at the surgical console. In other instances, fluid exhausted through thevent port220 may be exhausted from thevitrectomy probe200adirectly to the environment.

When the control jets supplied by the firstcontrol jet inlet404 and the secondcontrol jet inlet406 are inactive, the power stream from thepower stream inlet402 freely moves through theinteraction region408a.Thesplitter410 divides the power stream from thepower stream inlet402 into two separate flows. The separate flows are directed into thedistal pressure outlet412 and theproximal pressure outlet414, respectively. In this configuration, the pressure in both theproximal diaphragm chamber212aand thedistal diaphragm chamber212bare essentially equal. When a first control jet supplied to the firstcontrol jet inlet404 is active and a second control jet supplied to the secondcontrol jet inlet406 is inactive, the first control jet from the firstcontrol jet inlet404 interacts with the power stream from thepower stream inlet402 within theinteraction region408a.The resulting flow passes over thesplitter410 in such a way that the majority of the flow is redirected to thedistal pressure outlet412. The first control jet from the firstcontrol jet inlet404 is fluidically amplified by the power stream frompower stream inlet402. In this configuration, the pressure in thedistal diaphragm chamber212bis greater than the pressure in theproximal diaphragm chamber212a.This pressure differential causes theflexible diaphragm214 to become displaced in the direction ofarrow430, thereby actuating theinner cutter208 in the direction ofarrow430.

When the second control jet supplied to the secondcontrol jet inlet406 is active and the first control jet supplied to the firstcontrol jet inlet404 is inactive, the second control jet from the secondcontrol jet inlet406 interacts with the power stream from thepower stream inlet402 within theinteraction region408a.The resulting flow passes over thesplitter410 in such a way that the majority of the flow is redirected to theproximal pressure outlet414. The second control jet from the secondcontrol jet inlet406 is fluidically amplified by the power stream from thepower stream inlet402. In this configuration, the pressure in theproximal diaphragm chamber212ais greater than the pressure in thedistal diaphragm chamber212b.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow440, thereby actuating theinner cutter208 in the direction of thearrow440. The first and second control jets from the first and second

control jet inlets

404 and406 are alternatingly applied or cycled such that theflexible diaphragm214 andinner cutter208 continue to actuate in a reciprocal manner.

FIGS. 8 and 9 are schematic representations of additional example

fluidic amplifiers

400band400c,respectively. The

fluidic amplifiers

400band400cmay be used to actuate theinner cutter208 of thevitrectomy probe200ain place of thefluidic amplifier400a.FIGS. 8 and 9 illustrate how the geometry of the interaction region408 could be modified without changing the functionality of thefluidic amplifier400 or thevitrectomy probe200. For example, theinteraction region408bof thefluidic amplifier400bincludes two distinct regions. Flow from thepower stream inlet402, the firstcontrol jet inlet404, and the second control jet inlet406 (i.e., the power stream, the first control jet, and the second control jet, respectively) enters aproximal portion407 of theinteraction region408b.Flow circulates within thisproximal portion407 of theinteraction region408bbefore passing through adistal portion409 of theinteraction region408b.Otherwise,fluidic amplifier400bfunctions similarly to thefluidic amplifier400a,as described above.

Thefluidic amplifier400cincludes theinteraction region408cthat is aerodynamically shaped in order to take advantage of the Coanda effect, also referred to as “wall effects.” Flow from thepower stream inlet402, the firstcontrol jet inlet404, and the secondcontrol jet inlet406 enters theinteraction region408c.Both the shape of the walls of theinteraction region408cand the interaction between the power stream from thepower stream inlet402 and either of the control jets from the firstcontrol jet inlet404 or the secondcontrol jet inlet406 redirect flow in theinteraction region408c.Particularly, the first control jet interacts with the power stream to direct the combined flow into thedistal pressure outlet412 to increase pressure within thedistal diaphragm chamber212b,and the second control jet interacts with the power stream to direct the combined flow into theproximal pressure outlet414 to increase pressure within theproximal diaphragm chamber212a.Otherwise, thefluidic amplifier400cfunctions similarly to the

fluidic amplifier

400aand400b,as described above.

FIG. 10 is a schematic representation of a fluidic amplifier of a type included in thevitrectomy probe200b.Thefluidic amplifier500afunctions to actuate theinner cutter208 of thevitrectomy probe200b.Thefluidic amplifier500ais similar to thefluidic amplifier400aas shown inFIG. 7. In particular, thefluidic amplifier500aincludes apower stream inlet402, acontrol jet inlet404, asplitter410, adistal pressure outlet412, aproximal pressure outlet414, adistal vent line416, aproximal vent line418, and amain vent line420 that all function and interact in the same way as described above with reference toFIG. 7. However, thefluidic amplifier500aomits the secondcontrol jet inlet406, shown inFIG. 7, and includes a modifiedinteraction region408d.Thepower stream inlet402 is fluidically coupled to thepower stream port216. Thecontrol jet inlet404 is fluidically coupled to thecontrol jet port218. Thepower stream inlet402 and thecontrol jet inlet404 feed into aproximal end407 of theinteraction region408d.Thesplitter410 is located at adistal end409 of theinteraction region408dand redirects flow from thepower stream inlet402 and thecontrol jet inlet404. Thesplitter410 is offset from thepower stream inlet402 so that direct flow from thepower stream inlet402, i.e., the power stream, flows into theproximal pressure outlet414. As shown, thedistal pressure outlet412 is fluidically coupled to thedistal diaphragm chamber212b,and theproximal pressure outlet414 is fluidically coupled to theproximal diaphragm chamber212a.

When the control jet supplied by thecontrol jet inlet404 is inactive, the power stream from thepower stream inlet402 moves undeflected through theinteraction region408d.Thesplitter410 redirects the power stream from thepower stream inlet402 into theproximal pressure outlet414. As a result, the pressure in theproximal diaphragm chamber212abecomes greater than the pressure in thedistal diaphragm chamber212b.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow540, thereby actuating theinner cutter208 in the direction of thearrow540. When the control jet supplied to thecontrol jet inlet404 is active, the control jet fromcontrol jet inlet404 interacts with the power stream from thepower stream inlet402 within theinteraction region408d.The resulting flow passes over thesplitter410 in such a way that the majority of the flow is redirected to thedistal pressure outlet412. The control jet fromcontrol jet inlet404 is fluidically amplified by the power stream from thepower stream inlet402. As a result, the pressure in thedistal diaphragm chamber212bbecomes greater than the pressure in theproximal diaphragm chamber212a.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow530, thereby actuating theinner cutter208 in the direction of thearrow530. Cycling the control jet on and off results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 11 is a schematic representation of another fluidic amplifier of a type included in thevitrectomy probe200b.Thefluidic amplifier500bfunctions to actuate theinner cutter208 ofvitrectomy probe200b.Thefluidic amplifier500bis similar to thefluidic amplifier500ashown inFIG. 10. In particular, thefluidic amplifier500bincludes apower stream inlet402, acontrol jet inlet404, adistal vent line416, aproximal vent line418, and amain vent line420 that all function and interact in the same way as described above with reference toFIG. 10. However, thefluidic amplifier500bincludes aninteraction region508. Thepower stream inlet402 is fluidically coupled to thepower stream port216. Thecontrol jet inlet404 is fluidically coupled to thecontrol jet port218. Thepower stream inlet402 and thecontrol jet inlet404 feed into aproximal end507 of theinteraction region508. As shown, thefluidic amplifier500balso includes asplitter510, adistal pressure outlet512, and aproximal pressure outlet514. Thesplitter510 is located at adistal end509 ofinteraction region508 and redirects flow from thepower stream inlet402 and thecontrol jet inlet404. Alateral sidewall511 of theinteraction region508 is aerodynamically shaped in order to take advantage of the Coanda effect. Thesplitter510 is partially offset from thepower stream inlet402. As a result of the offset of thesplitter510 relative to thepower stream inlet402 and the shape of thelateral sidewall511 of theinteraction region508, the power stream from thepower stream inlet402, undeflected by a control jet, flows essentially entirely intodistal pressure outlet512. Thedistal pressure outlet512 is fluidically coupled to thedistal diaphragm chamber212b,and theproximal pressure outlet514 is fluidically coupled to theproximal diaphragm chamber212a.

Thedistal vent line416 is fluidically coupled to thedistal pressure outlet512. Thedistal vent line416 is positioned so that, when the pressure increases in thedistal chamber212b,excess pressure is vented, preventing backflow through theinteraction region508. Theproximal vent line418 is fluidically coupled to theproximal pressure outlet514. Theproximal vent line418 is positioned so that, when the pressure increases in theproximal chamber212a,excess pressure is vented, preventing backflow through theinteraction region508.

When the control jet supplied by thecontrol jet inlet404 is inactive, the flow, i.e., the power stream, frompower stream inlet402 moves undeflected throughinteraction region508 while remaining attached to thelateral sidewall511 of theinteraction region508 due to the Coanda effect. Thesplitter510 is positioned to direct the flow frompower stream inlet402 intodistal pressure outlet512. As a result, the pressure in thedistal diaphragm chamber212bincreases above the pressure in theproximal diaphragm chamber212a.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow530, thereby actuating theinner cutter208 in the direction of thearrow530. When the control jet supplied to controljet inlet404 is active, the control jet from thecontrol jet inlet404 interacts with the power stream from thepower stream inlet402 within theinteraction region508. This interaction interferes with the Coanda effect, and the power stream from thepower stream inlet402 detaches from thelateral sidewall511 ofinteraction region508. The resulting flow passes over thesplitter510 in such a way that the majority of the flow is redirected to theproximal pressure outlet514. The control jet fromcontrol jet inlet404 is fluidically amplified by the power stream from thepower stream inlet402. As a result, the pressure in theproximal diaphragm chamber212aincreases above the pressure in thedistal diaphragm chamber212b.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow540, thereby actuating theinner cutter208 in the direction of thearrow540. Cycling the control jet on and off results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 12 is a schematic representation of an example fluidic oscillator of a type included in thevitrectomy probe200c.Thefluidic oscillator600 functions to actuate theinner cutter208 of thevitrectomy probe200c.Thefluidic oscillator600 includes apower stream inlet602,

feedback channels

606aand606b,and aninteraction region604. Thepower stream inlet602 is fluidically coupled to thepower stream port216. Thepower stream inlet602 and the

feedback channels

606aand606bfeed into theproximal end603 of theinteraction region604. Thefluidic oscillator600 also includes anozzle608, asplitter610, adistal pressure outlet612, and aproximal pressure outlet614. Thenozzle608 is located at thedistal end605 of theinteraction region604. Thesplitter610 is located distal to thenozzle608 at thedistal end611 of thefluidic oscillator600 and redirects the power stream from thepower stream inlet602 after the power stream passes through theinteraction region604 and thenozzle608.

Thefluidic oscillator600 also includes afirst wall613, asecond wall615, a first taperedsidewall portion617 and a second taperedsidewall portion619. Thefirst wall613 includes a taperedwall portion621, and thesecond wall615 includes a taperedwall portion623. The tapered

wall portions

621 and623 taper to respective edges that define theproximal end603 of theinteraction region604. The first and second

tapered sidewall portions

617 and619 taper to respective edges that define thenozzle608.

The power stream from thepower stream inlet602 initially passes undeflected through theinteraction region604. However, the structure of thefluidic oscillator600, including thefirst wall613 and thesecond wall615 of theinteraction region604 and the firstpointed sidewall portion617 and secondpointed sidewall portion619 that form thenozzle608, introduce instabilities into the power stream frompower stream inlet602. For example, as the power stream from thepower stream inlet602 passes through a region between atapered wall portion621 of thefirst wall613 and atapered wall portion623 of thesecond wall615 of theinteraction region604, the power stream may be redirected toward thefirst wall613 by the taperedwall portion623 of thesecond wall615. As the redirected power stream continues through theinteraction region604, the redirected power stream may collide with thefirst wall613 and then continue toward thenozzle608. The power stream may then collide with the first taperedsidewall portion617 that forms thenozzle608. In this situation, thenozzle608 redirects some of the flow through thenozzle608 toward thesplitter610 and downward toward theproximal pressure outlet614. However, some of the flow may backup after colliding with the first taperedsidewall portion617 ofnozzle608. The backed up portion of the flow may cause flow to travel in the direction ofarrow630 throughfeedback channel606a.The flow fromfeedback channel606aalong with the taperedwall portion621 of thefirst wall613 of theinteraction region604 may then redirect the flow frompower stream inlet602 toward thesecond wall615 of theinteraction region604.

As the flow continues through theinteraction region604, the redirected flow may collide with thesecond wall615 and then continue toward thenozzle608. The flow may then collide with the second taperedsidewall portion619 that forms thenozzle608. In this situation, thenozzle608 redirects some of the flow through thenozzle608 toward thesplitter610 and upward toward thedistal pressure outlet612. However, some of the flow may backup after colliding with the second taperedsidewall portion619 of thenozzle608. The flow that has backed up may cause flow to travel in the direction ofarrow630 throughfeedback channel606b.The flow from thefeedback channel606balong with the taperedwall portion623 of thesecond wall615 of theinteraction region604 may then redirect the flow from thepower stream inlet602 toward thefirst wall613 of theinteraction region604. In this way, the flow from thepower stream inlet602 will continue to oscillate. This oscillation will cause the flow that exits from thenozzle608 to pass over thesplitter610 in such a way that the majority of the flow is redirected into either thedistal pressure outlet612 or theproximal pressure outlet614, depending on how the flow exits from thenozzle608. As shown, thedistal pressure outlet612 is fluidically coupled to thedistal diaphragm chamber212band theproximal pressure outlet614 is fluidically coupled to theproximal diaphragm chamber212a.Thefluidic oscillator600 also has adistal vent line616, aproximal vent line618, and amain vent line620 that function and interact in the same way as described above in reference toFIG. 2 throughFIG. 11.

When the power stream exits thenozzle608 in such a way that redirects the flow toward thesplitter610 and thedistal pressure outlet612, the pressure in thedistal diaphragm chamber212bbecomes greater than the pressure in theproximal diaphragm chamber212a.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of thearrow630, thereby actuating theinner cutter208 in the direction of thearrow630. When the power stream exits thenozzle608 in such a way that redirects the flow toward thesplitter610 and theproximal pressure outlet614, the pressure in theproximal diaphragm chamber212abecomes greater than the pressure in thedistal diaphragm chamber212b.This pressure differential causes theflexible diaphragm214 to become displaced in the direction of the arrow640, thereby actuating theinner cutter208 in the direction of the arrow640. Continuously supplying the power stream results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 13 is a schematic representation of a fluidic amplifier of a type included in thevitrectomy probe200dshown inFIG. 5. Thefluidic amplifier700afunctions to actuate theinner cutter208 of thevitrectomy probe200d.Thefluidic amplifier700ais similar to thefluidic amplifier500ashown inFIG. 10. In particular, thefluidic amplifier700aincludes apower stream inlet402, acontrol jet inlet404, and aninteraction region408e.Thepower stream inlet402 is fluidically coupled to thepower stream port216. Thecontrol jet inlet404 is fluidically coupled to thecontrol jet port218. Thepower stream inlet402 and thecontrol jet inlet404 feed into theproximal end407 of theinteraction region408e.As shown, thefluidic amplifier700aalso has asplitter708, anactive pressure outlet710, and anexhaust pressure outlet712. Thesplitter708 is located at thedistal end409 of theinteraction region408eand redirects flow from thepower stream inlet402 and thecontrol jet inlet404. Theactive pressure outlet710 conducts fluid that is used to actuate theflexible diaphragm214. Thesplitter708 is offset from thepower stream inlet402 so that direct flow frompower stream inlet402, i.e., the power stream, flows into theexhaust pressure outlet712. As shown, theactive pressure outlet710 is fluidically coupled to thediaphragm chamber312.

Thefluidic amplifier700aalso includes anactive vent line714 and amain vent line716. Theactive vent line714 is a vent line associated withactive pressure outlet710 that is used to conduct fluid to actuate theflexible diaphragm214. Theactive vent line714 is fluidically coupled to theactive pressure outlet710. Theactive vent line714 is positioned so that, when pressure increases in thediaphragm chamber312, excess pressure is vented through theactive vent line714 so as to prevent backflow through theinteraction region408e.As shown, theactive vent line714 and theexhaust pressure outlet712 are fluidically coupled to themain vent line716. Themain vent line716 is fluidically coupled to thevent port220. The fluid that is vented throughvent port220 is then exhausted at a location remote from thevitrectomy probe200d,for example, at the surgical console. In other instances, fluid exhausted through thevent port220 may be exhausted from thevitrectomy probe200ddirectly to the environment.

When the control jet supplied by thecontrol jet inlet404 is inactive, the power stream from thepower stream inlet402 moves undeflected through theinteraction region408e.Thesplitter708 is positioned to direct the power stream from thepower stream inlet402 into theexhaust pressure outlet712. As a result, the pressure in thediaphragm chamber312 is not sufficient to overcome the biasing force of the coil spring322 (shown inFIG. 5) and the flexible diaphragm214 (also shown inFIG. 5) either remains stationary or becomes displaced in the direction ofarrow730 due to the biasing force of thecoil spring322, thereby actuating theinner cutter208 in the direction of thearrow730. When the control jet supplied to thecontrol jet inlet404 is active, the control jet from thecontrol jet inlet404 interacts with the power stream from thepower stream inlet402 within theinteraction region408e.The resulting flow passes over thesplitter708 in such a way that the majority of the flow is redirected to theactive pressure outlet710. The control jet from thecontrol jet inlet404 is fluidically amplified by the power stream from thepower stream inlet402. This amplified pressure in thediaphragm chamber312 is sufficient to overcome the biasing force of thecoil spring322 and causesflexible diaphragm214 to become displaced in the direction of thearrow740, thereby actuating theinner cutter208 in the direction of thearrow740. Cycling the control jet on and off results in reciprocal actuation of theflexible diaphragm214 and inner cutter208 (shown inFIG. 5).

FIG. 14 is a schematic representation of a fluidic amplifier of a type included in thevitrectomy probe200d,shown inFIG. 5.FIG. 14 shows a variation of the example fluidic amplifier shown inFIG. 13. However, thesplitter708 of thefluidic amplifier700bis positioned aligned with thepower stream port216. Thesplitter708 of thefluidic amplifier700aofFIG. 13 is offset from thepower stream port216. In other implementations, the position of the splitter relative to the power stream port may be varied to achieve a desired output. Thefluidic amplifier700bfunctions to actuate theinner cutter208 of thevitrectomy probe200d.Thefluidic amplifier700bis similar to thefluidic amplifier700aas shown inFIG. 13. In particular, thefluidic amplifier700bincludes apower stream inlet402, acontrol jet inlet404, asplitter708, anactive pressure outlet710, anexhaust pressure outlet712, anactive vent line714, and amain vent line716 that all function and interact in the same way as described in reference toFIG. 13. However, thefluidic amplifier700bincludes aninteraction region408f.Thepower stream inlet402 is fluidically coupled to thepower stream port216. Thecontrol jet inlet404 is fluidically coupled to thecontrol jet port218. Thepower stream inlet402 and thecontrol jet inlet404 feed into theproximal end407 ofinteraction region408fThesplitter708 is aligned with thepower stream inlet402 so that direct flow from thepower stream inlet402 is equally split between theactive pressure outlet710 and theexhaust pressure outlet712.

When the control jet supplied by thecontrol jet inlet404 is inactive, the power stream from thepower stream inlet402 moves undeflected through theinteraction region408f.Thesplitter708 divides the power stream from thepower stream inlet402 into two separate flows. The separate flows are directed into theactive pressure outlet710 and theexhaust pressure outlet712, respectively. In this configuration, the pressure in thediaphragm chamber312 is not sufficient to overcome the biasing force of thecoil spring322, and theflexible diaphragm214 either remains stationary or becomes displaced in the direction ofarrow730 by the biasing force of thecoil spring322, thereby actuating theinner cutter208 in the direction ofarrow730. When the control jet supplied to thecontrol jet inlet404 is active, the control jet from thecontrol jet inlet404 interacts with the power stream from thepower stream inlet402 withininteraction region408fThe resulting flow passes over thesplitter708 in such a way that the majority of the flow is redirected to theactive pressure outlet710. The control jet from thecontrol jet inlet404 is fluidically amplified by the power stream from thepower stream inlet402. This amplified pressure in thediaphragm chamber312 is sufficient to overcome the biasing force of thecoil spring322 and causesflexible diaphragm214 to become displaced in the direction ofarrow740, thereby actuatinginner cutter208 in the direction ofarrow740. Cycling the control jet on and off results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 15 is a schematic representation of another fluidic amplifier of a type included in thevitrectomy probe200d,again, shown inFIG. 5. Thefluidic amplifier700cfunctions to actuate theinner cutter208 of thevitrectomy probe200d.Thefluidic amplifier700cis similar to thefluidic amplifier500bshown inFIG. 11. In particular, thefluidic amplifier700cincludes apower stream inlet402 and acontrol jet inlet404 that function and interact in the same way as described in reference toFIG. 11. However, thefluidic amplifier700cincludes aninteraction region806. Thepower stream inlet402 is fluidically coupled to thepower stream port216. Thecontrol jet inlet404 is fluidically coupled to thecontrol jet port218. Thepower stream inlet402 and thecontrol jet inlet404 feed into theproximal end805 of theinteraction region806. As shown, thefluidic amplifier700calso has asplitter808, anactive pressure outlet810, and anexhaust pressure outlet812. Thesplitter808 is located at thedistal end807 of theinteraction region806 and redirects flow from thepower stream inlet402 and thecontrol jet inlet404. Alateral sidewall809 of theinteraction region806 is aerodynamically shaped in order to take advantage of the Coanda effect. Thesplitter808 is partially offset from thepower stream inlet402. As a result of the offset of thesplitter808 relative to thepower stream inlet402 and the shape of thelateral sidewall809 of theinteraction region806, the power stream from thepower stream inlet402 flows essentially entirely into theexhaust pressure outlet812. As shown inFIG. 15, theactive pressure outlet810 is fluidically coupled to thediaphragm chamber312.

Thefluidic amplifier700calso includes anactive vent line814 and amain vent line816. Theactive vent line814 is fluidically coupled to theactive pressure outlet810. Theactive vent line814 is positioned so that, when pressure increases in thediaphragm chamber312, excess pressure is vented through the active vent line so as to prevent backflow through theinteraction region806. Both thedistal vent line814 and theexhaust pressure outlet812 are fluidically coupled to themain vent line816. Themain vent line816 is fluidically coupled to thevent port220. The fluid that is vented through thevent port220 is then exhausted at a location remote from thevitrectomy probe200d,for example, at the surgical console. In other instances, fluid exhausted through thevent port220 may be exhausted from thevitrectomy probe200ddirectly to the environment.

When the control jet supplied by thecontrol jet inlet404 is inactive, the power stream from thepower stream inlet402 moves undeflected throughinteraction region806 and remains attached to thelateral sidewall809 of theinteraction region806 due to the Coanda effect. Thesplitter808 is positioned to direct the flow from thepower stream inlet402 into theexhaust pressure outlet812. As a result, the pressure in thediaphragm chamber312 is not sufficient to overcome the biasing force of thecoil spring322, and theflexible diaphragm214 either remains stationary or is actuated in the direction ofarrow730 by the biasing force of theactuating spring322, thereby actuating theinner cutter208 in the direction ofarrow730. When the control jet supplied to thecontrol jet inlet404 is active, the control jet from thecontrol jet inlet404 interacts with the power stream from thepower stream inlet402 within theinteraction region806. This interaction interferes with the Coanda effect, and the power stream from thepower stream inlet402 detaches from thelateral sidewall809 of theinteraction region806. The resulting flow passes over thesplitter808 in such a way that the majority of the flow is redirected to theactive pressure outlet810. The control jet from thecontrol jet inlet404 is fluidically amplified by the power stream from thepower stream inlet402. This amplified pressure in thediaphragm chamber312 is sufficient to overcome the biasing force of thecoil spring322 and causesflexible diaphragm214 to become displaced in the direction of thearrow740, thereby actuatinginner cutter208 in the direction of thearrow740. Cycling the control jet on and off results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 16 is a schematic representation of an example fluidic oscillator of a type included in the vitrectomy probe200e,shown inFIG. 6. Thefluidic oscillator800 functions to actuate theinner cutter208 of the vitrectomy probe200e.Thefluidic oscillator800 is similar to the fluidic oscillator described in reference toFIG. 12. In particular, thefluidic oscillator800 includes apower stream inlet902,

feedback channels

906aand906b,aninteraction region904, anozzle908, asplitter910, anactive pressure outlet912, anexhaust pressure outlet914, afirst wall913, asecond wall915, anactive vent line916, anexhaust vent line918, and amain vent line920 that function and interact in the same way as the corresponding components of thefluidic oscillator600 described above in reference toFIG. 12. Thepower stream inlet902 is fluidically coupled to thepower stream port216. Thepower stream inlet902 and

feedback channels

906aand906bfeed into theproximal end903 of theinteraction region904.

When the power stream exits thenozzle908 in such a way that redirects the flow toward thesplitter910 and theactive pressure outlet912, the pressure indiaphragm chamber312 is sufficient to overcome the biasing force of thecoil spring322 and causes theflexible diaphragm214 to become displaced in the direction ofarrow840, thereby actuating theinner cutter208 in the direction ofarrow840. When the power stream exits thenozzle608 in such a way that redirects the flow toward thesplitter910 and theexhaust pressure outlet914, the pressure indiaphragm chamber312 is not sufficient to overcome the biasing force of thecoil spring322 and theflexible diaphragm214 either remains stationary or becomes displaced in the direction ofarrow830 by the biasing force of thecoil spring322. Continuously supplying the power stream results in reciprocal actuation of theflexible diaphragm214 and theinner cutter208.

FIG. 17 is a flowchart of anexample method1000 for actuating an inner cutter of a vitrectomy probe. Atstep1005, a power stream is supplied to a fluidic amplifier of a vitrectomy probe. The power stream may be supplied via a pressure line or any other appropriate supply structure. The power stream may be supplied at any appropriate or desired pressure level. For example, the power stream pressure level may be based on the characteristics of a diaphragm that is used in an actuating mechanism of the vitrectomy probe. The power stream pressure level may also be set in relation to the level of a control jet pressure, and vice versa. The power stream may result in deflection of a flexible diaphragm, such asflexible diaphragm214, for example, into either a distal or a proximal position which may depend on, for example, a configuration of the fluidic amplifier, a configuration of the vitrectomy probe, and/or other requirements of a user.

Atstep1010, a control jet is supplied to the fluidic amplifier of the vitrectomy probe. In some implementations, the control jet may be a single pulse. In other implementations, the control jet may be a series of pulses. In some instances, these series of pulses may be set to a cyclical pressure profile. The control jet may be supplied by any suitable or desired structure including, for example, by a pressure line, conduit, tubing, or other structure operable to conduct a fluid. The control jet may be supplied at a selected pressure level. The control jet may be cycled between a peak or maximum pressure and a minimum pressure. The minimum pressure of the control jet may be zero pressure or some pressure less than the maximum pressure. For example, in an off or inactive condition, the control jet is being applied at the minimum pressure. In an on or active condition, the control jet is being applied at the maximum or peak pressure. In some instances, the maximum or peak pressure of the control jet may be less than the pressure of the power stream. In some instances, the control jet pressure level may be based on the characteristics of the diaphragm that is used in the actuating mechanism of the vitrectomy probe, such as, for example, mass, rigidity, and/or configuration of the diaphragm. The control jet pressure level may also be set in relation to the level of the power stream pressure.

Atstep1015 andstep1020, the fluidic amplifier may be configured such that the control jet and the power stream cooperate to achieve the desired pressure distribution within a diaphragm chamber of the vitrectomy probe that houses the flexible diaphragm, such as, for example, the

diaphragm chambers

212 and312, described above. Atstep1015, the control jet is active such that the maximum pressure of the control jet is applied to the power stream. The interaction of the active control jet and the power stream may result in the majority of the power stream being redirected within the fluidic amplifier in such a way that results in actuation (e.g., deflection) of a flexible diaphragm, such asflexible diaphragm214. The flexible diaphragm may be actuated into a different position than a position than that associated with application of the power stream alone to the fluidic amplifier. The interaction of the active control jet and the power stream also results in an amplified output pressure that is greater than the control jet pressure.

As discussed in the detailed description ofFIG. 7 throughFIG. 11, the amplified output pressure results in a pressure differential across the flexible diaphragm, which deflects the flexible diaphragm and actuates the inner cutter, such asinner cutter208. The control jet pressure may be set at any desire level, such as a level sufficient to cause the flexible diaphragm to be actuated. For instance, a pressure of the control jet may selected to produce an amplified output pressure that causes an increase within the diaphragm chamber of, for example, less than 1%, less than 5%, or less than 10% of the power stream pressure. However, other output pressures are within the scope of the disclosure. The pressure of the control jet may be selected so as to cause other pressure differentials within the diaphragm chamber below, above, and between the indicated values are also within the scope of the disclosure. As discussed above in the context ofFIG. 13,FIG. 14, andFIG. 15, the amplified output pressure may result in a pressure within the diaphragm chamber that is sufficient to overcome the biasing force of the coil spring, such ascoil spring322, which allows the flexible diaphragm to actuate the inner cutter.

Atstep1020, the control jet is not active. Consequently, the control jet is being applied at the minimum pressure. The power stream is unaffected or, wherein the control jet pressure is greater than zero, minimally affected by the inactive control jet. The power stream is redirected within the fluidic amplifier and the flexible diaphragm returns to an initial or first position, which may be either a distal or proximal position as instep1005.

Atstep1025, the user may determine a desired cutting rate for the vitrectomy probe. In determining the desired cutting rate, the user may consider, for example, the stage of the vitrectomy procedure or the location within the eye where vitreous removal is desired. In some instances, the user may determine one or multiple desired cutting rates throughout the vitrectomy procedure. In some implementations, the user may desire a single cutting rate during a vitrectomy, and the vitrectomy probe may be operated to achieve an actuation cycle corresponding to a single cutting rate.

Atstep1030, the vitrectomy probe is configured such that the desired cutting rate for the vitrectomy probe is determined by and corresponds to a desired frequency of the control jet pressure that is supplied to the fluidic amplifier. The flexible diaphragm is responsive to the changes in the control jet pressure. The flexible diaphragm may be coupled to the inner cutter such that the inner cutter is actuated at the same frequency as the control jet pressure in response to actuation of the flexible diaphragm. In some instances, the inner cutter may be rigidly coupled to the flexible diaphragm. As such, the frequency of application of the control jet pressure to the power stream corresponds to and determines the cutting rate of the inner cutter.

Atstep1035, in order to achieve the desired cutting rate that was determined atstep1025, the frequency of application of the control jet pressure to the power stream may be set at the desired cutting rate. As a result, the vitrectomy probe will operate at the desired cutting rate as theinner cutter208 is actuated at the desired frequency.

Atstep1040, a pressure of the control jet supplied to the power stream may be selected so as to ensure that the flexible diaphragm is in a desired position at the conclusion of a vitrectomy procedure or when the vitrectomy probe is deactivated, such as, for example, when the user causes the vitrectomy probe to cease operation of the cutter. This pressure to ensure the desired positioning of the diaphragm may be referred to as a final pressure profile. For example, the user may desire that the aspiration port be open before removing the vitrectomy probe from the eye. Ensuring that the aspiration port be open may prevent damage to the eye caused by unsevered vitreous strands held by the cutter and still attached to the eye. To ensure an open aspiration port such as by retraction of the inner cutter, the control jet is either applied or not applied to the power stream depending on, for example, the configuration of the fluidic amplifier, the configuration of the vitrectomy probe, and/or on the requirements of the user. After supplying the final pressure profile, the vitrectomy procedure may be concluded, and the vitrectomy probe may be removed from the eye.

Althoughmethod1000 illustrates an example process for actuating an inner cutter of a vitrectomy probe, other methods for actuating the inner cutter may include fewer, additional, and or a different arrangement of operations. For example, a method may omit one or more of the described steps, such as, for example, steps1025,1030,1035, or1040. Still further, the arrangement of steps illustrated inFIG. 17 may be varied from that described above and shown inFIG. 17.

FIG. 18 is a flowchart of anexample method1100 for actuating an inner cutter of a vitrectomy probe. Atstep1105, a power stream may be supplied to a fluidic oscillator of a vitrectomy probe. The power stream may be supplied via a pressure line, conduit, tubing, or other structure operable to conduct a fluid. The power stream may be supplied at a selected pressure level. The power stream pressure level may be based on, for example, the characteristics of the diaphragm that is used in the actuating mechanism of the vitrectomy probe. The power stream may result in actuation (e.g., deflection) of the flexible diaphragm into either a distal or proximal position. Actuation of the flexible diaphragm into either the distal or proximal position may be based on a configuration of the fluidic oscillator, a configuration of the vitrectomy probe, and/or on other requirements of the user.

At

steps

1110 and1115, the fluidic oscillator may be configured such that the power stream interacts with feedback channels within the fluidic oscillator to achieve the desired pressure distribution within a diaphragm chamber that houses the flexible diaphragm, such asdiaphragm chamber212 or thediaphragm chamber312. Atstep1110, a first feedback channel is active. A first feedback pressure resulting from the first feedback channel may be at a peak. As a result of the first feedback pressures, the flexible diaphragm may be actuated into a different position than an initial position. The initial position of the flexible diaphragm may correspond to the position of the flexible diaphragm that results from application of the power stream unaffected by feedback pressure. The interaction of the first feedback channel and the power stream may result in the majority of the power stream being redirected within the fluidic oscillator in such a way that theflexible diaphragm214 is actuated (e.g., deflected). As discussed in the detailed description associated withFIG. 12, the power stream causes a pressure differential across the flexible diaphragm, which actuates the inner cutter. A pressure of the power stream may be selected so as to cause the flexible diaphragm to be actuated. For instance, the power stream pressure may be selected so as to result in a pressure differential within the diaphragm chamber of, for example, less than1%, less than 5%, or less than 10% of the power stream pressure. Again, though, other output pressures are within the scope of the disclosure. The pressure of the power stream may be selected so as to cause other pressure differentials within the diaphragm chamber below, above, and between the indicated values are also within the scope of the disclosure. As discussed in the detailed description ofFIG. 16, the power stream may result in a pressure within the diaphragm chamber that is sufficient to overcome the biasing force of the coil spring, which allows the flexible diaphragm to actuate the inner cutter.

Atstep1115, a second feedback channel is active. A second feedback pressure resulting from the second feedback channel may be at a peak. In response to the second feedback pressure, the flexible diaphragm may be actuated into a position different than that associated with the first feedback pressure and different from that resulting from the power stream unaffected by the first or second feedback pressures. The power stream is redirected within the fluidic oscillator due to the second feedback pressure, causing the flexible diaphragm to be actuated in a direction opposite to that caused by the first feedback pressure. As the power stream continues to be supplied to the fluidic oscillator, the power stream will continue to interact with the internal structure of the fluidic oscillator, e.g., the feedback channels, creating the first and second feedback pressures and causing the power stream to oscillate in response thereto. As long as the power stream is supplied to the fluidic oscillator, the power stream will continue to oscillate and actuate diaphragm in a reciprocating manner.

Atstep1120, the user may determine a desired cutting rate for the vitrectomy probe. In determining the desired cutting rate, the user may consider, for example, the stage of the vitrectomy procedure or the location within the eye where vitreous removal is desired. In some instances, the user may determine one or multiple desired cutting rates throughout the vitrectomy surgery. The user may also desire a single cutting rate during a vitrectomy, and the vitrectomy probe may be operated to achieve an actuation cycle corresponding to a single cutting rate.

Atstep1125, the vitrectomy probe is configured such that the desired cutting rate for the vitrectomy probe is determined by and corresponds to a desired frequency of the power stream oscillation within the fluidic oscillator. The flexible diaphragm is responsive to the changes in the power stream. The flexible diaphragm may be coupled to the inner cutter such that the inner cutter is actuated at the same frequency as the power stream oscillation in response to the flexible diaphragm. In some instances, the inner cutter may be rigidly coupled to the flexible diaphragm. As such, the frequency of the power stream oscillation corresponds to and determines the cutting rate of the inner cutter.

Atstep1130, in order to achieve the desired cutting rate that was determined atstep1120, the frequency of the power stream oscillation may be set at the desired cutting rate. Generally, with the use of a fluidic oscillator, the fluidic oscillator would be designed to operate at a desired, fixed frequency. With the use of a fluidic amplifier, the frequency of operation may be adjusted based on the frequency at which the control jet is operated. As a result, the vitrectomy probe will operate at the desired cutting rate as theinner cutter208 is actuated at the desired frequency.

Atstep1135, a pressure of the power stream supplied to the fluidic oscillator may be selected in order to ensure that the flexible diaphragm is in a desired position at the conclusion of a vitrectomy procedure or when the vitrectomy probe is deactivated, such as, for example, when the user causes the vitrectomy probe to cease operation of the cutter. This pressure to ensure the desired positioning of the diaphragm may be referred to as a final pressure profile. For example, the user may require that the aspiration port be open before removing the vitrectomy probe from the eye. As explained above, ensuring that the aspiration port is in an open condition may prevent injury to the eye. To ensure an open aspiration port, such as by retraction of the inner cutter, the power stream is prevented from being supplied to the fluidic oscillator at the appropriate time based on, for example, the configuration of the fluidic oscillator, the configuration of the vitrectomy probe, and/or on the requirements of the user. After supplying the final pressure profile, the vitrectomy procedure may be concluded, and the vitrectomy probe may be removed from the eye.

Althoughmethod1100 illustrates an example process for actuating an inner cutter of a vitrectomy probe, other methods for actuating the inner cutter may include fewer, additional, and or a different arrangement of operations. For example, a method may omit one or more of the described steps, such as, for example, steps1125,1130, or1135. Still further, the arrangement of steps illustrated inFIG. 18 may be varied from that described above and shown inFIG. 18.

The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosure. For example, although the above systems and methods are discussed in the context of actuating a vitrectomy probe, a similar system may be used to actuate other surgical instruments that employ fluidic actuators. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Claims

1. A vitrectomy probe comprising:

a body defining a first diaphragm chamber;

a cutter comprising:

a tubular outer cutter coupled at a proximal end of the body; and

a tubular inner cutter disposed within the tubular outer cutter and movable therewithin;

an actuating mechanism comprising:

a flexible diaphragm coupled to the body, the first diaphragm chamber disposed adjacent to a first side of the flexible diaphragm; and

a fluidic amplifier comprising:

an interaction region;

a supply port in fluid communication with the interaction region, the supply port operable to introduce a power stream of fluid into the interaction region;

a first control port in fluid communication with the interaction region, the first control port operable to introduce a first control jet of fluid into the interaction region;

a vent port through which fluid is vented from the fluidic amplifier;

a splitter disposed at a distal end the interaction region and dividing the distal end of the interaction region into a first outlet and a second outlet, the first outlet fluidically coupled to the first diaphragm chamber and the second outlet fluidically coupled to the vent port; and

a first vent line fluidically coupled to the first outlet of the interaction region and fluidically coupled to the vent port.

2. The vitrectomy probe ofclaim 1, further comprising a spring positioned on a second side of the flexible diaphragm opposite the first side, the spring configured to apply a biasing force to the flexible diaphragm.

3. The vitrectomy probe ofclaim 1, wherein the splitter is offset from the supply port such that the splitter redirects a flow from the supply port into the first outlet.

4. The vitrectomy probe ofclaim 1, wherein the splitter is offset from the supply port such that the splitter redirects a flow from the supply port into the second outlet.

5. The vitrectomy probe ofclaim 1, wherein the interaction region comprises a sidewall shaped to promote attachment of the power stream to the sidewall.

6. The vitrectomy probe ofclaim 1, wherein the splitter is aligned with the supply port such that the splitter redirects a flow from the supply port substantially equally into the first outlet and the second outlet.

7. The vitrectomy probe ofclaim 1, further comprising:

a second diaphragm chamber disposed adjacent to a second side of the flexible diaphragm, the second outlet fluidically coupled to the second diaphragm chamber; and

a second vent line extending from the second outlet to the vent port.

8. The vitrectomy probe ofclaim 7, wherein the splitter is offset from the supply port such that the splitter redirects a flow from the supply port into the first outlet of the interaction region.

9. The vitrectomy probe ofclaim 7, wherein the interaction region comprises a sidewall shaped to promote attachment of the power stream to the sidewall.

10. The vitrectomy probe ofclaim 1, wherein vitrectomy probe further comprises:

a second control port fluidically coupled to the interaction region, the second control portion operable to introduce a second control jet into the interaction region; and

wherein the splitter is aligned with the supply port such that the splitter divides a power stream flow from the supply port substantially equally into the first outlet of the interaction region and the second outlet of the interaction region.

11. A method for actuating a cutter of a vitrectomy probe, the method comprising:

supplying a power stream to a fluidic amplifier disposed within the vitrectomy probe, a tubular inner cutter of the cutter disposed in a first position when the power stream is supplied to the fluidic amplifier; and

selectively supplying a control jet to the fluidic amplifier with such that when the control jet is supplied, the power stream is redirected from a first path to a second path within the fluidic amplifier to actuate the tubular inner cutter from the first position to a second position, and when the control jet is not supplied, the power stream is returned to the first path within the fluidic amplifier, causing the tubular inner cutter to return to the first position.

12. The method ofclaim 11, further comprising:

determining a desired cutting rate of the cutter;

configuring the fluidic amplifier such that the desired cutting rate of the cutter corresponds to a desired frequency of the control jet that is supplied to the fluidic amplifier; and

setting the desired cutting rate for cutter by setting the control jet to a desired frequency.

13. A vitrectomy probe comprising:

a body defining a first diaphragm chamber;

a tubular outer cutter coupled at a proximal end to the body;

an aspiration port formed in a distal end of the tubular outer cutter;

a tubular inner cutter disposed within the tubular outer cutter, the tubular inner cutter movable within the tubular outer cutter; and

an actuating mechanism operable to actuate the tubular inner cutter, the actuating mechanism housed in the body and comprising:

a fluidic oscillator comprising:

an interaction region;

a vent port through which fluid is vented from the fluidic oscillator;

a first feedback channel offset from the interaction region by a first wall, the first feedback channel operable to redirect the power stream of fluid in a first direction;

a second feedback channel offset from the interaction region by a second wall, the second feedback channel operable to redirect the power stream in a second direction opposite the first direction;

a nozzle at the distal end of the interaction region;

a first outlet extending from the nozzle and fluidically coupled to the first diaphragm chamber;

a second outlet extending from the nozzle and fluidically coupled to the vent port; and

a first vent line fluidically coupled to the first outlet of the fluidic oscillator and fluidically coupled to the vent port.

14. The vitrectomy probe ofclaim 13, further comprising:

a second diaphragm chamber disposed on a second side of the flexible diaphragm opposite the first side; and

a second vent line extending from the second outlet to the vent port, wherein the first outlet of the fluidic oscillator is fluidically coupled to one of the first diaphragm chamber or the second diaphragm chamber; and

wherein the second outlet of the fluidic oscillator is fluidically coupled to the other of the first diaphragm chamber or the second diaphragm chamber.

15. The vitrectomy probe ofclaim 13, further comprising a spring abutting the flexible diaphragm along a second side of the flexible diaphragm opposite the first side.

16. The vitrectomy probe ofclaim 13, wherein the fluidic oscillator further comprises a splitter that separates the first outlet from the second outlet.